Children will be at an increased risk of cancer and birth defects should a planned gas processing and petrochemicals plant in Darwin Harbour go ahead, doctors have warned.

Dozens of healthcare professionals converged on Parliament House in Canberra on Tuesday to urge the federal government to withdraw $1.5 billion in funding for the Middle Arm industrial hub in Darwin.

The expansion of fossil fuel projects, including fracking in the Beetaloo Basin, will adversely affect the wellbeing of communities and push an exhausted healthcare system beyond breaking point, they said.

Northern Territory-based paediatrician Louise Woodward wants to meet with Prime Minister Anthony Albanese to present international research showing the health risks posed to humans living close to oil and gas production.

"Air pollution from these gas projects affects children and pregnant women ... so we will be expecting increased rates of leukaemia and other blood cancers," she said.

Dr Woodward has also written to NT Chief Minister Natasha Fyles asking her to reconsider approving fracking in the Beetaloo Basin.

The letter points to scientific studies showing children living near fracking operations in the US have higher rates of low birth weight, birth defects, childhood cancers and respiratory conditions.

A second letter asks Mr Albanese to intervene, prevent the fracking and withdraw taxpayer cash from Middle Arm.

About 2300 health professionals have signed the letter to the prime minister, which has the backing of Australia's medical colleges.

Representatives met Assistant Minister for Indigenous Australians Malarndirri McCarthy to present their concerns.

Mr Albanese defended his government's funding for Middle Arm, saying it was important for several renewable energy and critical minerals projects.

"The Australian government's proposed investment ... is not for any company, it's not for any product, it's for public infrastructure," he said in parliament on Tuesday.

He did not address the health concerns.

Independent senator David Pocock blasted Labor for supporting a project that will "turn Darwin into Australia's very own Cancer Alley".

"This is a negligent decision from our government," he said.

Senator Pocock said the Albanese government had picked up Scott Morrison's "gas-led recovery".

Dr Woodward said international studies had documented the impacts of petrochemical factories, including a 30 per cent increased risk of leukaemia, which predominantly affects children, for populations within 5km.

Darwin woman Kat McNamara is pregnant with her third child and was among the territory parents who protested for a "safe, healthy future in the NT".

Ms Fyles said there were plenty of safeguards to protect human and environmental health and a large amount of work had been done that would help assess risks and monitor and mitigate impacts on the Beetaloo region.

The chief minister, who last week railed against "teals and trolls" spreading nonsense about Middle Arm, said the project was a renewable energy hub that would help decarbonise the economy.

NT Treasurer Eva Lawler said her government would ensure Middle Arm goes through the "most stringent environmental assessment".

Dr Woodward called a baseline population assessment in the Beetaloo area "extremely low quality" and next to useless when it comes to tracking future human health impacts.